pledge vs guarantee

pledge and guarantee both are nouns.

Word	Noun	Adjective	Verb	Adverb
pledge	Yes	No	Yes	No
guarantee	Yes	No	Yes	No

As nouns, guarantee is a hyponym of pledge; that is, guarantee is a word with a more specific, narrower meaning than pledge:

pledge: a binding commitment to do or give or refrain from something
guarantee: a written assurance that some product or service will be provided or will meet certain specifications

Other hyponyms of pledge include warrant, warrantee, warranty, plight, troth, vow.

As verbs, guarantee is a hyponym of pledge; that is, guarantee is a word with a more specific, narrower meaning than pledge:

Other hyponyms of pledge include vow, vouch, covenant, covenant.

pledge (noun)	guarantee (noun)
a binding commitment to do or give or refrain from something	a written assurance that some product or service will be provided or will meet certain specifications
a drink in honor of or to the health of a person or event	an unconditional commitment that something will happen or that something is true
someone accepted for membership but not yet fully admitted to the group	a collateral agreement to answer for the debt of another in case that person defaults
a deposit of personal property as security for a debt

pledge (verb)	guarantee (verb)
promise solemnly and formally	give surety or assume responsibility
bind or secure by a pledge	promise to do or accomplish
give as a guarantee	stand behind and guarantee the quality, accuracy, or condition of
propose a toast to	make certain of
pay (an amount of money) as a contribution to a charity or service, especially at regular intervals